Autotractor.



P. E. HOLT.

AUTOTRACTOR.

APPLICATION HLEI OCT. 16, .91:.

May 1-5, 1915,

4 SHEETS-SHEET I.

Patented Int 0111 3041 glut L 5% P. E. HOLT AUTOTRACTOR.

APPLICATION men on 16. 1912.

4 SHEETS-SHEET 2.

Patented My 25, 1915.

L Lo bl? b F P. E. HOLT.

AUTOTRACTOR.

APPLlCATiON FILED on t6. 1912.

Patented May 25, 1915.

4 SHEETS SHEET 3.

' Patented May 25, 1915.

4 SHEETS-SHEET 4.

:4 A; river 1 fi PLINY E. HOLT, 0F PIEDlVIOIl'T, CALIFORNIA.

AUTO TRACTOR.

Specification of Letters Patent.

Patented May 25, 1915.

Application filed October 16, 1912. Serial No. 726,087. 7

1 '0 all whom it may, concern Be it known that I, PLiNr E. How, a citizen of the United States, and a resident of the city of Piedmont, county of Alameda, and State of California, have invented new and useful Improvements in Autotractors, of which the following is a specification.

This invention relates to auto-tractors and more particularly to improvements,. i n the steering mechanism thereof for the control of trailers towed behind the tractor.

The objects sought to be accomplished are to combine a traction mechanism, a steering mechanism and machines of mechanical utility in an interdependent working combination with a centralized control, with a further object of bringing agricultural, frcighting and other traction operations under the immediate control of a single operator. Herctofore it lias been the usual practice to produce theauto-tractor as -n independent 'niachine capable of being hitched to the general types of traction utilities. This results in an aggregation of elements in a general way cotiperative but ill-suited to meet the demands of economical operation.

The problem of steering an-auto-tractor involves two principles, the pressure 'Qf gravity on the pilot wheels to give them traction, and horizontal leverage to give the tractor direction. Theoreticallithe pilot wheel or wheels should be the fulcrum point of the lever. The power is represented by the progressive inertia of the tractor; there fore, the fulcrum should be as nearas Inechanically practical-to the load or point of greatest resistance. Circumlocution being proverbial in the workings of the laws of evolution, the development of the auto-tractor in the greater percentage of cases shows the pilot wheel in front as aconcession to precedents established in the horse drawn vehicle. The auto-tractor being a pushed vehicle or the reverse of a drawn-vehicle, the front pilot Wheel appears absurd for many reasons. It is a recognized fact in any drawn load that the burden is reduced by applying the draft with a slight lift- .mg action, for this reason a wagon should be loaded heavy in front.' In a wagon the prime mover pre z-des the pilot wheels that are carrying the major load. The same principles are involved in mechanical tracas tion, it is logical that the pilot wheel shduld be behind the tractive element, for the very obvious reason that the lifting tendency between the draft bar and the load tends to elevate pilot wheels located in front and to a. considerable extent destroy their function. This logic is substantiated in the workings of nature, the steering appurtenances are to the rear of the power in all birds of flight, h, animals, reptiles, etc. Acting upon this discovery, applicant has embodied it in his invention grouping the tractor element, the steering element and the load element into an interacting wor ing combination whereby the functioning of each element contributes as much as may be to the proper working of the whole.

Broadly stated, this invention consists of a traction element of the caterpillar type, having a steering truck pivoted thereto, pilot wheels pivoted on said truck, means for synchronously swinging the steering truck about its pivot and thepilot wheels about their pivots; the steering mechanism being interposed between the traction element and the load element; whereby the, load clementexerts a downward pressure upon the steering truck and through it a downward pull on the traction element.

In the drawings, Figure 1 is a plan view from above of a tractor constructed in accordance with this invention and combined with a power-lift plow' 'Qpmsenting the load element. Fig. 2 is a side'elcvation of the same. Fig. 3 is an end eleyation of the steering-truck with'the plow detached.

Fig. 4 is a fragmentai; detail in plan from beneath the tumbling s aft, extending from its engagement with the motive mechanism rearward to the power lift mechanism of the plow. Fig. 5 is a fragmentary view partially ii -cross section, looking at the end of the steering w'orm"mounted upon the steering truck and enmeshed with the gear tia'lly in cross" section taken on the 1-inch above of the steering mechanism shown in the positions assumed in the maximum lateral swing.

In detail the construction consists of the pilot wheels 1 mounted upon journal stubs ments in rounding curves.

The rear end of the tractor main frame is provided with the cross bar having the lateral extensions 9 and 10, and the center portion 11, outwardly curved, its radius being struck from the pivotal center 7 of the steering truck. The rack segment 12 is at tached to the cross bar 11. The bracket 13 carrying the roller 14 is fixed on the drawbar 6. The roller 14: impinges upon the flange 15 of the crossbar 11 and the upper surface of the rack 12 to maintain horizontal alincment between the traction and the steering elements. The gear-worm 16 is mounted between the brackets 17 mounted upon the'drawbar 6. This worm is enmeshed with the rack segment 12, fixed upon the main frame of the tractor. Rotation is transmitted from the hand wheel 18 through the column 19 and the miter gears 20 and 21 respectively fixed upon the column 19 and the shaft 22 of the gear worm. The

function of the worm and sector is to swing the steering truck to the right or left, with respect to the traction element at the will of the operator. The steering knuckle spin dles 3 are provided with the steering arms 23 and 24, rigidly fixed thereon. These steering arms are caused to act in unison by the cross-bar 25, the opposite ends of which are pivoted to the steering arms. To cause the proper tracking of the pilot wheels behind the traction belts 26 in following the differential arcs, it is necessary to reverse the angle of travel of these two elements, that is, in making a turn to the right the pilot wheels are swung to the left about their pivots 3 while the traction mechanism is caused to swing to-the right about the pivot 7. This is accomplished by the swinging arm 27 pivoted at 2-8 on the draw-bar 6. The front end is connected to the extension 9 on the main frame by the connecting link 20. The ratio of divergence in the differential are being determined by the point 30 where the connecting link 31 is pivoted to the swinging arm 27 and the end of the steering arm 23. As the steering truck is swung about its pivot on the traction mechanism, the pilot wheels are swung on their pivots on the steering axle. The proper ratio is maintained throughout the arc. The angle of resistance of the pilot wheels to the line of progress of the traction mechanism causes the latter to swing at an angle determined by the pilot wheels.

The pilot wheels are provided with the upstanding flange to increase the resistance. The traction mechanism is provided with a differential. gearing 38 to facilitate turning as is common in this art. The horizontally pivoted steering truck is provided with the stay-rods 3; extending from opposite ends of the truck to the draw-bar to give lateral rigidity to the structure. The draft bar 35 engages the yoke 36 attached to the draw-bar. The rearward extension of the bar comprises two straps 37 and 38, that pass respectively above and below the cross brace 39 on the steering truck. The stop bolts 40 limit the lateral swing of the draftbar. This play is allowed to permit slight lateral deviations of the tractor, without affecting the trailer.

The tractor is driven by the prime mover or, having a driving inion enmeshed with an internal gear 41, or imparting reduced speed to the main transmission shaft 42,

meshed with internal gears fixed to the main driving sprockets 43. These sprockets engage the traction belts 26, that encircle traction trucks composed of the driving sprockets journaled to the main frame, idle sprockets 44, bracketed to the main frame and intermediate rollers 45 resiliently at tached to the main frame and adapted to carry the major portion. of the weight of the tractor as they roll upon the upper side of the ground portion of the traction belt that is drawn under them by the driving sprockets.

Combined with the above described traction mechanism and steering mechanism is a gang plow depending upon the traction mechanism for its forward progress and for its raisingand lowering power and upon the steering mechanism for the direction of I its progress and for partial support. The plow consists of the main frame having the standards 46 upon which the plow base 47 are mounted. The forward end of the plow frame is attached to the draft bar 35 by the coupling pin t8 engaging the coupling 49. The bolt 50 extending between the plates 51 and 52 engages'the coupling 49. The running nuts 53 provide vertical adjustment of the coupling. The forward end of the plow frame is thus supported upon the steering truck. The plow is provided with the rollers 54 mounted upon the radius rods 55 which extend forward and are pivoted in the block 57 fixed upon the front end of the plow frame. The rack bars 58 and-59 are pivoted near these rollers and extend upward and engage the pinions 60 and 61 fixed on the shaft 62 journaled in the base 63 mounted upon the plow frame. The shaft 62 is provided with a worm gear 72 and clutch merhanism 73 geared to the tumbling shaft (it. The tumbling shaft is provided with the universal joint 63 and the slip joint 66 and the universal joint 67, and is mounted in suitable journal boxes on the raster main frame. The tumbling shalt rereives ts rotation through the gear os splined thereon and enmeshed with the gear 69, enmeshed with the pinion 70 fixed upon the transmission shaft that geared to the prime mover. Rotation is thus transmitted from the prime mover to the raising and lowering mechanism on the plow, within n'ianual control of the operator through the clutch control lever 71.

The control of the whole mechanism is oa'itralized at or near the spring seat 93 for the operator. From his position he can (control the main clutch through the handle i l the various speed changing levers and throttle mechanisms (not shown) of the prime mover; the steering mechanism through the wheel 18 or the plowing mesh .uiisn'i l'hri'iugh the lever Tl. Other manual operations are in the nature of fixed asijustments not necessarily under the imme diate control of the operator. The rear wheel ('39 controlling the tumbling shat to the plow is splined so that this gear can he thrown out of mesh when rotation of the tumbling shaft is unnecessary. Sprockets and chain may he substituted for the gear train if desired.

A. plow has been illustrated and desoriherl as the third element in the combination, but :ipplicl'in'r does not Wish to be confined to this later I'neehanism in the interpretation of his invention. Soon other agricultural implement, asharvesters. hinders, reapers mowing and other machines that might (lo-- rive their povi or through the tumbling: haft can in) trailed behind as substitutes for the plow or in ('omhination with each other hehind the steering mechanism. The traction and steering mechanism Will Work in com liination with Wagons single or entrain, the steering wheels acting as the front truck of the first wagon, succeeding Wagons being provided with similar steering trucks, if it is desired to form a close coupled train capable of turning in a short radius. In this instance the tumbling shaft can be connrrted to auxiliary traction mechanisms on the wagons.

lly my in ention the leverage of the trailer in turning a corner is exerted against the pilot wheel and not against the engine frame as would be the case ii the trailer were pivoted directly to the engine frame in the usual manner. As a result my trailer were omitted.

Having thus what is claimed lif Letters l 1 The eomhn a main frame. merits and into: prime mover and steering mocha: pivoted on the liar-ti mout fixed on the ti: worm cmneshod WE mounted upon the tatiiig the gear wow the drawliar, uh axle. pilot wheels axles, and a. connecting rod arms, a sivh'iging S ur piv t har and linked to i wotima.

guided by tin Z. The Combination o a tiaetor t'ran'ie, a. mechanisms and posed between the mover and traction mechanism; a draw lair iiiVim-i on the tractor frame; a Ynlk nien he l upon the tractor he. "worm era-- int-she'll with the. lo. znozi it t upon the draw i.-a= Ul llil n' 'iz n the draw liar. pilot the said axle. m ans i inn the draw lmr :ili

pilot wheels aliout the v 3. A tract r nrlo. e

prime mover. t

ulilo gearingnnz' ll.

pivoted upon. l la-nine, an ax! ol'oll upon the dr axles upon said axle, pil t 1 l -vls jiVf'lifilk the stub axles: a :wi'h wyjinont ii the main frame, mounted upon the with the rook oted .1 ion the (IXRW la:- main irnrne and (tonne, stuh axles.

4. A tractor inclini prime mover. traction iai sion gearing interim mover the traction row-l bar pivote ll upon the main on said draw bar, stil said axle, pilot when stub axles, a connecting: nectedivith said stall at lever pivoted upon said to said stub a. es and it'll; metal frame.

liaiisiililr the :1 The combinafiion of a tractor supported upon an midlc flexible traction member; a tractor" frame, a draw bar pivoted to the tractor frame, a steering truck mounted upon said draw bar and having a pilot wheel mounted upon :1 vertical pivot and means by which the draw bu! is shifted from side to solo and thc pi ot wheel is synchronously turned on its vertical pivot.

6. The combination of a tractor frame snpporml upon an cndloss flexible traction moznbcr, r1 draw bar pivoted to tho tractor frame. a steering truck pivoted on said draw bar, and including :1 pilot wheel mounted upon :1 wriical pivo n moons for synchronously moving-z the draw: our about its pivot and tho oiiot whorl about. iis pivot 7, In combination tli 11 tractor, a stccring olomcnt min m Airing a: draw bin" pivoted to the tractor, bltlzll'flg truck attached to the draw l ar, and luring a pilot, wheel pivotod thereon, a steering means for said pilot Wheel ands shifting mechanism inifirposed between said drz'm' bar and the tractor, and oonnoctcd to tl'xrsnoring means for said pilot wheel.

8. In a tractor, the combination with a tractor frame ozn'rying an engine and traction wheels, of roar steering truck pivotally connected with the tractor frame on a vertical axis, and embod; ing mooring; wheels pivotally connected with the steering truck on vertical axes locntcd in roar of tho pivotal connection between the truck and tractor frame, and moons whereby a swing-- ing movement imparted to the soaring i'rnol with relation to the Lracior ironic iin mm: a synchronous swinging: movement ixw steering Wheels on their individual :1 i

2'). In a tractor. the combination with :2 tractor frame carrying on engine and trawl; members driven by the engine, of a sicorii truck pivotally conncot od with the trxu. frame in proximity to the drive slmft of twin: tractor, and embodying piloi. nlinols v nnlod to swing on vcrticoi @105 (:1? id on ing truck in rear of the trocror Home, for swinging he steering trnri; and tract/or frame laterally with relation to moi; otlwr, and means for simultaneously sninging illo pilotwheels on their vertical axes in syn chronism with the relatiw movomcnt of n; truck and frame.

Kim

PLI N Y "I. H 0 ill W itnesses F. G.,HoLT, C. F. Horn; 

